Optical record carrier recording apparatus

ABSTRACT

The present invention relates to an optical record carrier ( 55 ) recording apparatus ( 5 ) such as a small form factor optical drive and to a portable device ( 1 ), such as a mobile phone or a palmtop computer, comprising such an optical record carrier ( 55 ) recording apparatus ( 5 ). To enable different accessing modes having different data rates depending on the power mode of the recording apparatus an appropriate switching means ( 53 ) is provided in the recording apparatus for switching accessing means ( 54 ) for accessing an optical record carrier ( 55 ) for reading data from or recording data to said optical record carrier ( 55 ) between said accessing modes. A first accessing mode has a low data rate and is used in a low power mode while a second accessing mode has a high data rate and is used or allowed to be used in a high power mode.

The present invention relates to an optical record carrier recordingapparatus, in particular to a small form factor optical drive, andfurther to a portable device, such as a mobile phone or a palmtopcomputer.

One of the great challenges of a small form factor optical drive to beused in a portable device is the reduction of the power consumption. Forwriting in such a recording apparatus the record carrier, particularlythe disc, needs to be rotated, a laser is pulsed using a writing IC andother electronics need to be powered. As most applications in a mobileenvironment, where the portable device is intended to be used, like e.g.MP3 or MPEG4 video, do not require a high bandwidth, power can be savedusing burst mode writing and reading.

The basic idea of burst mode writing and reading is that the drive canoperate at a relatively high bit rate or speed range, e.g. 1× Blu-rayDisc standard 36 Mbps, which is, however, never used all the time. Usingbuffering means the data is e.g. read back in a short time interval,after which the low data rate application like MP3 can play the data outof the buffer until the buffer needs to be filled again. During thisplayback time, the drive can be put into a low power mode, e.g. byputting writing and reading circuitry in a stand-by mode and turning offthe disc rotation motor. Typical peak powers can be of the order 1 W,whereas an average power for a 1 Mbps application can be as low as 50mW. A typical battery could run more than 20 hours with the constant 1Mbps bit rate, depending on motor spin up time. Further, the burst modehas some redundancy using some extra energy. Besides that the batteryemptying is a non-linear process. For instance, in a mobile phone thetotal battery has a capacity of 600 mAh or sometimes more, which is alsoneeded to power the phone.

For writing of a single small data file, for instance an MP3 file, theopposite can be used and the data can directly be written from a filledbuffer. The latter option can be sufficient for a mobile environment, asthe bandwidth of downloading via wireless communications like GSM or 3GUMTS hardly exceeds a few Mbps.

When looking at the use of current CD-R and CD-RW record carriers, itturns out that a significant number of people use an optical disc systemfor downloading large amounts of data, copying large music collectionsor simply directly copying of complete CDs storing data and/or music. Inorder to do so consumers want to download or copy information torecordable or rewritable record carriers at a reasonable speed.Consumers do not want to wait hours or even more than several minutesuntil the record carrier is completed which is achieved by high speed CDrecording apparatuses.

In a mobile environment, however, the high data rate required for suchapplications means either a continuously working optical drive at e.g.36 Mbps (1×) or even operation at a higher data rate and disc speed,e.g. 3×36 Mbps (3×). This will quickly empty a battery or, which is evenmore important, will not be available in the portable device at all dueto power limitations. For instance, in a best case situation, a typical600 mAh battery would be exhausted after, at maximum, 10 disc downloadsof 1 GB, each taking 4 mins. Therefore, downloading at a high speed andhigh data rate without power limitations would indeed fill a need ofconsumers.

U.S. Pat. No. 5,412,809 describes a disc drive power control circuit andmethod for controlling electric power consumption in disc drives so thatcomputer systems such as laptop computers can conserve power, and as aresult can dramatically reduce the effective life of batteries employedas a power source of the computer systems. The user is allowed to adoptthe performance versus power consumption to meet the systemrequirements. Transient currents associated with initiation ofmechanical cooperation such as an actuator for actuating a magnetic headand a spindle motor for rotating a magnetic disc at high speed withoptimum access time and starting time, respectively, are effectivelycontrolled.

It is an object of the present invention to provide an optical recordcarrier recording apparatus which solves the above described problemsand which enables the use of high data rate applications.

This object is achieved according to the present invention by an opticalrecord carrier recording apparatus as claimed in claim 1 comprising:

-   -   an accessing means for accessing an optical record carrier for        reading data from or recording data to said optical record        carrier,    -   a switching means for switching said accessing means between at        least two accessing modes having different data rates depending        on the power mode of the recording apparatus, wherein said        accessing means are switched into a first accessing mode having        a lower data rate than a second accessing mode when the        recording apparatus is in a low power mode.

The present invention relates further to a portable device as claimed inclaim 9 which, besides such an optical record carrier recordingapparatus, further comprises:

-   -   a data interface for transmitting and receiving data,    -   a battery unit for internal supply in a first power supply mode,        and    -   a power interface for connecting to a an external power supply        unit for external power supply in a second power supply mode.

The present invention is based on the idea to enable the accessing meansfor accessing the record carrier, i.e. read and/or writing means forreading from and/or writing to the record carrier, to operate in atleast two different power modes, i.e. to have different data rates andbandwidths depending on what kind of power is supplied to the recordingapparatus. Generally, in a low power mode the accessing means shall beoperated in a first accessing mode with a low data rate to save powerwhile in a high power mode a second accessing mode having a higher datarate can be enabled by appropriate switching means. For instance, in amobile environment, where the recording apparatus is supplied with powerfrom a battery, which can also be an accumulator, the recordingapparatus is optimised to have a low power consumption, i.e. theaccessing means are operated in the first accessing mode having a lowdata rate. However, if the recording apparatus or the portable device towhich the recording apparatus is attached, is supplied with externalpower the data rate can be increased strongly, thus allowing a highspeed download functionality to the portable device. In such a highpower mode enough electrical power is available so that a disc used asrecord carrier can be rotated continuously and writing can occur at amuch higher speed than would ever be available in a portable device dueto its burst writing scenario described above. It is even possible tohave the recording apparatus optimised in the way that the disc motorcan run at an even higher speed than in the mobile environment andelectronics of the recording apparatus can be clocked up in order toattain an even higher download speed.

Preferred embodiments of the invention are defined in the dependentclaims. Particularly, different embodiments of the switching means aredefined.

According to a first preferred embodiment the switching means areadapted for detecting the power mode of the recording apparatus from thepower supplied. Thus, independent of the power source for power supplyof the recording apparatus, in case the power supplied falls below apredetermined value the accessing means can be switched into the firstaccessing mode having a low data rate to save power. On the contrary, ifthe power supplied is above said predetermined value, the high data rateshall be allowed, for instance if an application or a user requires it.

According to another embodiment an information identifying the powermode of the recording apparatus is provided to it which information canbe received and evaluated by the switching means. For instance, a signalor an identifier provided from the portable device to which therecording apparatus is attached can be provided including theinformation if a high or a low power mode is available, for instance, ifthe power is supplied from an internal battery or an external powersource.

Preferably, as defined in further dependent claims, in case of a batterypower supply mode the accessing means are switched into the firstaccessing mode having a low data rate while they are switched into asecond accessing mode when the recording apparatus is in a mains powersupply mode. Further accessing modes, for instance an accessing modehaving an intermediate data rate between the low and high data rate arepossible as well.

As mentioned above, the recording apparatus according to the inventionis preferably applied in a portable device such as a telephone, inparticular a mobile phone or a cordless phone, or a palmtop computer(PDA). Moreover, the recording apparatus is preferably a small formfactor optical drive. Devices typically having the previously describedintermediate data rate and power mode can be e.g. digital camcorders,digital cameras or laptops, sublaptops and handheld devices where therequirements of data rate of typically 10 Mbps are realistic but wherealso the battery or accumulator exceeds by far 1000 mAh, simply becausebattery packs are larger but also performance demands are higher.

The invention also relates to an alternative embodiment of a recordingapparatus as claimed in claim 8 which does not contain switching meansbut an accessing mode interface for receiving a command from an externaldevice, e.g. the mobile phone in which the recording apparatus isprovided, which instructs the recording apparatus to switch in theappropriate accessing mode. In this case the external device, i.e. theportable device, comprises the mode switching means as defined in claim10.

The invention will now be explained in more detail with reference to thedrawings in which

FIG. 1 shows a mobile phone according to the present invention,

FIG. 2 shows a recording apparatus according to the present invention.

FIG. 3 shows another embodiment of a mobile phone according to thepresent invention, and

FIG. 4 shows another embodiment of a recording apparatus according tothe present invention.

FIG. 1 shows a mobile phone 1 as one example of the portable device inwhich the invention can be implemented. The mobile phone 1 comprises adata bus 2 to which a data interface 3 for transmitting and receivingdata via a cordless or corded connection, a data processing means 4,such as a digital signal processor (DSP), a small form factor opticaldrive 5 and a data transmitting and receiving unit 6 for high frequencymobile data transmission and reception are connected. The mobile phone 1further comprises a power interface 7 to which an external power source,e.g. an AC/DC power adaptor connected to a mains supply can beconnected. Further a battery (or accumulator) 8 is provided as internalpower supply when the mobile phone 1 is used in a mobile environmentwhere no external power is supplied at the power interface 7. A powerswitch 9 is provided to switch between the two power supplies 7 and 8and to provide the elements of the mobile phone 1 with power asindicated by the broken lines. The power switch 9 is adapted to providepower supplied at power interface 7 in case an external power source isconnected there. Otherwise battery power of the battery 8 is used. Forcontrol of the elements of the mobile phone 1 a control unit 10 isprovided.

More details of the small form factor optical drive 5 are shown in theblock diagram of FIG. 2. The drive 5 comprises a data interface 51connected to the bus 2 of the mobile phone 1 for data input and output.Further, the drive 5 comprises a power interface 52 connected to thepower switch 9 of the mobile phone 1 for power supply of the drive 5.

A mode switch 53 is provided to switch, depending on the power suppliedat power interface 52 the accessing unit 54 between different accessingmodes during reading data from and/or writing data to a record carrier55, which is a small form factor optical disc in this embodiment.

In case the mobile phone 1 is connected to an external power supply, forinstance a mains supply, the accessing unit 54 of the drive 5 can beoperated in a high data rate accessing mode. Because in this case enoughelectrical power is available the disc 55 can be rotated continuouslyand writing can be performed at a much higher speed compared to the lowdata rate accessing mode which is performed in the low power mode whenthe mobile phone 1 is supplied with power from the battery 8. In thehigh power mode it is even possible to have the drive's architectureoptimised in the way that the disc motor can run at an even higher speedthan in the mobile environment, and the electronics of the drives 5 canbe clocked up in order to attain an even higher data rate allowingdownloads of data in an even shorter time.

In order to switch between the different accessing modes the mode switch53 must know in which kind of power mode the mobile phone 1 is or whichkind of power is available to the drive 5. One possibility is that themode switch 53 can detect the voltage level of the power supplied atpower interface 52 and switch into the low data rate accessing moderequiring less power if the voltage supplied is below a predeterminedthreshold voltage. This will be the case in the battery supply mode ifthe battery voltage has already dropped by a certain amount. Anotherpossibility is that the power switch 9 of the mobile phone 9 provides,in addition to the power itself, an information to the drive 5indicating which power mode is currently available in the mobile phone1, i.e. indicating battery power supply mode or mains power supply mode.Based on this information the mode switch 53 will be able to switch theaccessing unit 54 into the appropriate accessing mode or, for instance,prohibit a high data rate accessing mode in case power is supplied fromthe battery only.

A mode switch can also be switched by a command, for instance of a user,by an application itself, e.g. software driven as a function of arequired data rate demand, or by another event such as the connection ofa power chord to the power interface 7 of the mobile phone 1. Forinstance, if the mobile phone 1 is attached with a power chord and adata link, either wired or wireless, to a computer, for which a cradlewith conventional interface can be used, the accessing unit 54 can beautomatically switched into a high data rate accessing mode or it can beallowed to switch into this accessing mode.

FIG. 3 shows another embodiment of a mobile phone 1 according to theinvention comprising another embodiment of a drive 5′ which isillustrated in FIG. 4. In this embodiment the mode switch 11 is notprovided in the drive 5′ but external of it as part of the mobile phone1. Depending on the power received from the power switch 9 the modeswitch 11 switches the drive 5′ into the appropriate accessing mode, forinstance by generating a command forwarded to the drive 5′ via the modeinterface 56 of drive 5′. This command is, for instance, generated inresponse to attaching or detaching of a power chord to the mobile phone1. Thus, the mobile phone 1 decides about the accessing mode and thedrive 5′ follows.

The present invention allows the operation of the small form factoroptical drive in different modes enabling different data rates and thusdifferent writing or reading speeds. In a low power mode power iseffectively saved by switching into a low data rate accessing mode whilein a high power mode high speed writing and reading are available.

1. An optical record carrier recording apparatus comprising an accessingmeans for accessing an optical record carrier for reading data from orrecording data to said optical record carrier, and a switching means forswitching said accessing means between at least two accessing modeshaving different data rates depending on the power mode of the recordingapparatus, wherein said accessing means are switched into a firstaccessing mode having a lower data rate than a second accessing modewhen the recording apparatus is in a low power mode.
 2. An opticalrecord carrier recording apparatus as claimed in claim 1, wherein saidswitching means are adapted for detecting the power mode of therecording apparatus from the power supplied.
 3. An optical recordcarrier recording apparatus as claimed in claim 2, wherein saidswitching means are adapted for switching said accessing means into saidfirst accessing mode when the power supplied is below a predeterminedvalue.
 4. An optical record carrier recording apparatus as claimed inclaim 1, wherein said switching means are adapted for receiving andevaluating an information identifying the power mode of the recordingapparatus.
 5. An optical record carrier recording apparatus as claimedin claim 4, wherein said information is received from an externaldevice, in particular including a command to instruct said switchingmeans to switch between into one of said accessing modes depending onthe power mode of the external device.
 6. An optical record carrierrecording apparatus as claimed in claim 1, wherein said switching meansare adapted for switching said accessing means into said first accessingmode when the recording apparatus is in a battery power supply mode. 7.An optical record carrier recording apparatus as claimed in claim 1,wherein said switching means are adapted for switching said accessingmeans into said second accessing mode when the recording apparatus is inmains power supply mode.
 8. An optical record carrier recordingapparatus comprising an accessing means for accessing an optical recordcarrier for reading data from or recording data to said optical recordcarrier, and an access mode interface for receiving a command from anexternal device for switching said accessing means between at least twoaccessing modes having different data rates depending on the power modeof the external device, wherein said accessing means are switched into afirst accessing mode having a lower data rate than a second accessingmode when the external device is in a low power mode.
 9. Portable devicecomprising a data interface for transmitting and receiving data, abattery unit for internal supply in a first power supply mode, a powerinterface for connecting to a an external power supply unit for externalpower supply in a second power supply mode, and an optical recordcarrier recording apparatus as claimed in claim 1 for storing data on orreading data from a record carrier.
 10. Portable device as claimed inclaim 9, further comprising a switching means for generating andtransmitting a command to said optical record carrier recordingapparatus for switching said accessing means between at least twoaccessing modes having different data rates depending on the power modeof the portable device, wherein said accessing means are switched into afirst accessing mode having a lower data rate than a second accessingmode when the portable device is in a low power mode.
 11. Portabledevice as claimed in claim 9, wherein said portable device is atelephone, in particular a mobile phone or a cordless phone, a palmtopcomputer, a laptop, a digital camera or a camcorder.
 12. Portable deviceas claimed in claim 9, wherein said optical record carrier recordingapparatus is a small form factor optical drive.